Fabrication of Zn and Mn loaded activated carbon derived from corn cobs for the adsorptive desulfurization of model and real fuel oils

Herein we report the fabrication of Zn and Mn loaded activated carbon (AC) derived from corn cobs for the adsorptive desulfurization of model and real fuel oils. Energy dispersive X-ray spectroscopy, Brunauer-Emmett-Teller surface area (S-BET) analysis, scanning electron microscopy and Fourier transform infra-red spectroscopy results revealed that the prepared adsorbents possessed oxygen functionalities, porous morphology and large S-BET (257 m(2)/g). Preliminary adsorption experiments were accomplished by utilizing 0.15 g adsorbent dosage, 2 h contact time at 30 degrees C, which removed 95.7% of dibenzothiophene (DBT) associated with a significant decrease in S-BET of the spent Zn/AC and Mn/AC (from 257 to 193 m(2)/g and 42 to 32 m(2)/g respectively). An overall DBT removal performance order of: Zn/AC > Mn/AC > AC was observed. Kinetics investigations disclosed that adsorption process follows pseudo 2nd order kinetics and Freundlich adsorption isotherm model. Zn/AC and Mn/AC adsorbents remained highly active for six repeated cycles with minimal decrease in the desulfurization performance. Under the optimized reaction conditions, 92% DBT from kerosene and 50% from gasoline were removed by the prepared adsorbents. This study provides a cost-effective adsorbent for the effective desulfurization of model and real fuel oils on large scale fuel oil processing.

Automated summary

In this study, zinc and manganese loaded activated carbon derived from corn cobs were used for adsorptive desulfurization of model and real fuel oils. The results showed that Zn/AC and Mn/AC performed better in removing dibenzothiophene, following pseudo 2nd order kinetics and Freundlich adsorption isotherm model. The prepared adsorbents remained highly active for six repeated cycles with minimal decrease in desulfurization performance under the optimized reaction conditions.